Imaging characteristics, misdiagnosis and microsurgical outcomes of patients with spinal dural arteriovenous fistula: a retrospective study of 32 patients

Advances in imaging modalities for spinal tumors

The spinal cord occupies a narrow region and is tightly surrounded by osseous and ligamentous structures; spinal tumors can damage this structure and deprive patients of their ability to independently perform activities of daily living. Hence, imaging is vital for the prompt detection and accurate diagnosis of spinal tumors, as well as determining the optimal treatment and follow-up plan. However, many clinicians may not be familiar with the imaging characteristics of spinal tumors due to their rarity. In addition, spinal surgeons might not fully utilize imaging for the surgical planning and management of spinal tumors because of the complex heterogeneity of these lesions. In the present review, we focus on conventional and advanced spinal tumor imaging techniques. These imaging modalities include computed tomography, positron emission tomography, digital subtraction angiography, conventional and microstructural magnetic resonance imaging, and high-resolution ultrasound. We discuss the advantages and disadvantages of conventional and emerging imaging modalities, followed by an examination of cutting-edge medical technology to complement current needs in the field of spinal tumors. Moreover, machine learning and artificial intelligence are anticipated to impact the application of spinal imaging techniques. Through this review, we discuss the importance of conventional and advanced spinal tumor imaging, and the opportunity to combine advanced technologies with conventional modalities to better manage patients with these lesions.

An Update on Spinal Dural Arteriovenous Fistulae: Case Series and Systematic Review

Spinal dural arteriovenous fistulae (sDAVFs) are rare entities with delayed diagnosis, potentially dramatic clinical manifestations, and complex management. We aim to present our mini case series and perform an updated systematic review of the usual patient profile, to search for established prognostic factors, to compare the effectiveness and safety of surgical and endovascular intervention, and to discuss trends in therapeutic strategy. We retrospectively collected data from patients treated in our department in the last decade (2014-2024) and we systematically reviewed the literature according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) criteria and searched the PubMed database for relevant articles published in the same period. Epidemiologic data, imaging modalities, prognostic factors, and treatment modalities were assessed. Firstly, we identified four illustrative cases from our institution. In addition, our search yielded 559 studies and our review included 82 original studies. 3130 patients were identified (mean age 61; male-to-female ratio 3:1). Most commonly, the fistula level was in the thoracic spine (65%). Surgery was provided to 1837 patients (1213 as primary treatment) and embolism to 1085 (932 as primary treatment). Initial fistula occlusion rate and recurrence rate were 98.1% and 1.9% for surgery and 71.1% and 9.6% for embolism, respectively. No difference between the two modalities with respect to clinical outcome was observed. SDAVFs remain a challenge for neurosurgeons concerning both diagnosis and management. Surgery remains superior to embolism with respect to success as an initial treatment. Embolism can be offered if certain contraindications do not coexist. All symptomatic patients should be offered treatment, whereas asymptomatic patients could be conservatively managed only if the close patient follow-up can be secured.

Spinal Dural Arteriovenous Fistula with Low Back Pain as the Only Symptom at Onset: A Case Report

BACKGROUND Spinal cord arteriovenous fistula that only manifests as lower back pain is easily misdiagnosed as myofasciitis, lumbar spondylosis, and other diseases, and incorrect treatment such as glucocorticoid blockade might be given, leading to worsening of the condition. CASE REPORT We analyze the clinical characteristics of a patient with spinal dural arteriovenous fistula who presented with chronic-onset low back pain. A patient with spinal dural arteriovenous fistula presented with chronic-onset low back pain as the only symptom, and was misdiagnosed as having myofasciitis. We assessed the paraclinical data, clinical reasoning, and course of treatment. The patient was an elderly man with low back pain for 1 year. He was diagnosed with myofasciitis in a local hospital and received local blocking treatment using glucocorticoid, and left lower-limb weakness appeared after that. After he was admitted to our hospital, enhanced thoracic and lumbar magnetic resonance imaging and selective spinal angiography were performed, and the results indicated the diagnosis of spinal dural arteriovenous fistula. After surgical treatment, the low back pain and lower-limb weakness were alleviated, and the patient is still under follow-up. CONCLUSIONS The possibility of spinal dural arteriovenous fistula should not be overlooked among patients with chronic low back pain, and caution should be taken when using glucocorticoids for treatment of chronic low back pain.

Application of Spinal Subtraction and Bone Background Fusion CTA in the Accurate Diagnosis and Evaluation of Spinal Vascular Malformations

BACKGROUND AND PURPOSE

Accurate pretreatment diagnosis and assessment of spinal vascular malformations using spinal CTA are crucial for patient prognosis, but the postprocessing reconstruction may not be able to fully depict the lesions due to the complexity inherent in spinal anatomy. Our purpose was to explore the application value of the spinal subtraction and bone background fusion CTA (SSBBF-CTA) technique in precisely depicting and localizing spinal vascular malformation lesions.

MATERIALS AND METHODS

In this retrospective study, patients (between November 2017 and November 2022) with symptoms similar to those of spinal vascular malformations were divided into diseased (group A) and nondiseased (group B) groups. All patients underwent spinal CTA using Siemens dual-source CT. Multiplanar reconstruction; routine bone subtraction, and SSBBF-CTA images were obtained using the snygo.via and ADW4.6 postprocessing reconstruction workstations. Multiple observers researched the following 3 aspects: 1) preliminary screening capability using original images with multiplanar reconstruction CTA, 2) the accuracy and stability of the SSBBF-CTA postprocessing technique, and 3) diagnostic evaluation of spinal vascular malformations using the 3 types of postprocessing images. Diagnostic performance was analyzed using receiver operating characteristic analysis, while reader or image differences were analyzed using the Wilcoxon signed-rank test or the Kruskal-Wallis rank sum test.

RESULTS

Forty-nine patients (groups A and B: 22 and 27 patients; mean ages, 44.0 [SD, 14.3] years and 44.6 [SD,15.2] years; 13 and 16 men) were evaluated. Junior physicians showed lower diagnostic accuracy and sensitivity using multiplanar reconstruction CTA (85.7% and 77.3%) than senior physicians (93.9% and 90.9%, 98% and 95.5%). Short-term trained juniors achieved SSBBF-CTA image accuracy similar to that of experienced physicians (P > .05). In terms of the visualization and localization of spinal vascular malformation lesions (nidus/fistula, feeding artery, and drainage vein), both multiplanar reconstruction and SSBBF-CTA outperformed routine bone subtraction CTA (P = .000). Compared with multiplanar reconstruction, SSBBF-CTA allowed less experienced physicians to achieve superior diagnostic capabilities (comparable with those of experienced radiologists) more rapidly (P < .05).

CONCLUSIONS

The SSBBF-CTA technique exhibited excellent reproducibility and enabled accurate pretreatment diagnosis and assessment of spinal vascular malformations with high diagnostic efficiency, particularly for junior radiologists.

Diagnosis of spinal dural arteriovenous fistula: a multimodal MRI assessment strategy

AIM

To identify more specific screening indicators at magnetic resonance imaging (MRI) for the diagnosis of spinal dural arteriovenous fistulas (SDAVFs) and to determine an efficient diagnostic strategy.

MATERIALS AND METHODS

This retrospective study analysed clinical and imaging data of patients diagnosed with SDAVF and alternative myelopathy who underwent conventional MRI examinations. Additionally, three-dimensional (3D) T2-weighted sampling perfection with application-optimised contrasts using different flip-angle evolutions (3D-T2-SPACE) and contrast-enhanced magnetic resonance angiography (CE-MRA) data from patients with SDAVF were compared with digital subtraction angiography (DSA) data.

RESULTS

The age of onset, perimedullary flow voids (PFV), distribution of lesions, syringomyelia, degree of spinal oedema, and cauda equina disorder (CED) were factors that showed statistically significance in the identification of SDAVF with alternative myelopathy. After controlling for age, gender, PFV, degree of spinal cord swelling, and syringomyelia, the multivariable ordinal logistic regression model showed that the CED sign (OR = 32.46; 95% confidence interval [CI]: 2.47-427.15; p=0.008) was an independent predictor for SDAVF. The diagnostic model constructed using the PFV and CED signs had better diagnostic performance, with an area under the curve of 0.957 (p<0.001), maximum Youden index of 0.844, sensitivity of 92.9%, and specificity of 91.5%. Both 3D-T2-SPACE (77.8%) and CE-MRA (83.3%) sequences had good localisation values for SDAVF. Combining the two imaging examinations had better diagnostic accuracy than that of DSA.

CONCLUSION

CED and PFV on conventional MRI were specific indicators for the diagnosis of SDAVF. To compensate for the lack of fistula localisation on conventional MRI, 3D-T2-SPACE and CE-MRA can be used. Together they complement each other and have good diagnostic potential.

The value of 3D T2-weighted SPACE sequence in the differential diagnosis of spinal arteriovenous fistula and acute transverse myelitis

OBJECTIVE

Spinal arteriovenous fistulas (SAVF) was often neglected and misdiagnosed as acute transverse myelitis (ATM) due to its insidious onset and non-specific clinical symptoms. This study aims to investigate the differential diagnostic value of high-resolution T2-weighted volumetric sequence (3D sampling perfection with application-optimized contrasts using different flip-angle evolutions [SPACE]) in patients with SAVF and ATM.

METHODS

Retrospectively analyzed the clinical and radiological findings of 32 SDAVF patients and 32 ATM patients treated at our institutions from May 2018 to January 2023. They all underwent conventional spinal MRI and T2-SPACE examination, compared their performance in identifying lesions, to estimate the value of T2 SPACE sequence in the diagnosis of SAVF and ATM patients.

RESULTS

The clue of cauda equina area change (CEAC) in conventional MRI and T2-SPACE sequences is specific for the diagnosis of SAVF. The diagnostic model composed of perimedullary flow voids (PFV) and CEAC has good diagnostic performance (AUCMRI = 0.95; AUCSPACE = 0.935). Compared with conventional MRI, the T2-SPACE sequence has a higher detection rate, sensitivity, and negative predictive value for PFV and CEAC in SAVF patients, but lower specificity and positive predictive value. In T2-SPACE images, there are significant differences in the distribution range, quadrant, and maximum diameter of PFV vessels between SAVF and ATM patients. Moreover, T2-SPACE sequence can determine the site of fistula in most SAVF patients preferably, and the inter-rater agreement was good in the assessment of the fistula.

CONCLUSION

The CEAC is a new and useful clue for the diagnosis of thoracolumbar SAVF. And T2-SPACE sequence can more intuitively observe the lesions of SAVF, has good differential diagnostic value for SAVF and ATM patients.

Clinical outcomes and prognostic factors in the surgical treatment of spinal dural arteriovenous fistulas: a retrospective study of 118 patients

Spinal dural arteriovenous fistulas (SDAVFs) are the most common type of spinal vascular malformations (AVMs), constituting approximately 70% of all spinal AVMs. The impact of various clinical and radiologic features on the outcomes in patients with SDAVFs is still controversial. The purpose of the study is to investigate the clinical outcomes and prognostic factors in patients with surgically treated SDAVFs in a single center. A retrospective review was performed for all patients with SDAVFs from January 2013 to September 2021 who underwent surgery at our institution. Medical records and pre- and postoperative imaging data were analyzed. Neurological function status was evaluated by modified Aminoff-Logue Scale (mALS). Student's t-test, Wilcoxon rank sum test, χ2 test and logistic regression were used to find significant prognostic factors. P values < 0.05 were considered significant. One hundred and eighteen patients were ultimately included in the study. By comparing preoperative and postoperative mALS, 69 (58.5%) patients experienced improvement, and 49 (41.5%) patients showed no improvement (worse or unchanged). Wilcoxon rank sum test showed that there was a difference between the improvement group and the no improvement group in preoperative mALS Micturition score and preoperative mALS Defecation score. The logistic regression revealed that preoperative mALS Gait score was associated with clinical improvement after surgery in patients with SDAVFs. Surgical treatment of SDAVFs is a safe and effective procedure and can lead to symptom improvement or stabilization in most patients. Preoperative neurological function status was the only factor associated with clinical prognosis.